Detective Lieutenant Chin Ho Kelly is a former member of the Hawaii Five-0 Task Force and a former highly decorated HPD cop before being wrongly accused of corruption which resulted in his career and reputation being tarnished.
For a short time, after Governor Pat Jameson's murder and Hawaii Five-0 being disbanded, Chin temporarily joined the Honolulu Police Department once again but after Steve was cleared, Hawaii Five-0 was reopened and Chin officially rejoined the team.
Born and raised in Hawaii, Chin lived a relatively normal life and during his time in high school, befriended teenage Steve McGarrett.
At some point, in his later adult years, Chin joined the Honolulu Police Department but his career was ultimately left in tatters as he took the fall for his uncle, Keako who had stolen money as Keako's wife and Kono and Chin's aunt, Mele was gravely ill and needed a kidney.
Not wanting his uncle to be shamed, Chin took the fall with many of his former officers regarding Chin as a thief.
After resigning from the HPD, Chin became a security guard with the fallout prompting him to leave his fiancée, Dr. Malia Waincroft for her protection.
In the Pilot (episode), Chin was reunited with Steve and instantly agreed to join the unnamed Task Force, Chin's technological skills and knowledge of Hawaii in general giving the team a huge advantage.
In Season Two, Chin proposed to his former fiancee, Dr. Malia Waincroft, and the two were later married in a beach ceremony, in the company of their friends and family.
He and Detective Danny Williams join forces with NCIS Special Agent G. Callen and Special Agent Sam Hanna to stop a smallpox outbreak from happening during Pa Make Loa (episode) with both teams heading to Los Angeles to stop a worldwide pandemic from occurring in the concluding episode, Touch of Death (episode).
In the finale, he was forced to choose between rescuing his wife or cousin.
In the premier, Malia died from her wounds, leaving Chin devastated although he later avenges her death while the team is later seen at her funeral (3.02). In the finale, he called Leilani out for a date.
In Hana Lokomaika'i, Chin is questioned by Internal Affairs about his contact with Gabriel Waincroft. It is tense for Chin because Gabriel is Malia's brother and Chin tried to protect Gabriel when they were younger. It is later revealed that Gabriel killed Chin's father.
In an alternate reality seen in Ina Paha (episode), as a result of the Hawaii Five-0 Task Force not being created, the Chin of that reality is presumably still highly respected and admired as a Detective.
As such, he has been promoted to Captain and also maintains a high position in the Honolulu Police Department.
In Pilina Koko during the murder investigation of a young mother it is discovered that Gabriel Waincroft is her daughter's father. This means that Chin finds out that he has a niece named Sara Waincroft. Later in Pa'a Ka 'Ipuka I Ka 'Upena Nananana before Gabriel dies he reconciled with Chin and ask him to take care of Sara.
In 7.01 it is revealed that Chin has been taking care of Sara. They are having breakfast making pancakes when a women knocks at the door. She says that she is from DCFS and that they have found Sara's aunt and uncle who live in Mexico. They are working to get custody of Sara.
In 7.11 Chin and the rest of Five-0 go to Mexico when it is discovered that Sara has been kidnapped. It is discovered during the course of the investigation that Sara was not the target, it was Five-0. Chin gives himself up to the bad guys in a trade him for Sara. Five-0 ends up saving Chin in the next episode 7.12. Maria and Jorge give Chin custody of Sara. Chin, Sara and the rest of Five-0 return to Mexico.
Danny Williams: You heard from Kono?
Steve McGarrett: Yeah, I have. Yeah, I spoke to her a couple days ago. Seems like, every time she locks up a perp, they get new Intel that leads to another arrest. She's even brought in Chin's San Fran task force to handle the West Coast operations. What?
Danny Williams: No, it's just weird. I mean, I miss those guys, you know?
Steve McGarrett: Yeah, me too. Look who's a sensitive little flower now. 
Tani Rey: Come on. You gotta be kidding me.
Steve McGarrett: I'm serious man, he got locked out of his room with nothing but a towel and his abs.
Tani Rey: Oh, my God.
Steve McGarrett: Yeah, You don't believe me, ask-ask, uh... ask Duke.
Tani Rey: I'm sorry, Duke was there?
Steve McGarrett: Yeah. Yeah, Duke was there. And his wife. You know, his wife bought him a gym membership right after that. Duke's been mad at Chin's ever since.
Tani Rey: Oh, my God. When am I gonna met this guy?
Steve McGarrett: You'll meet him.
Tani Rey: Chin Ho?!
Steve McGarrett: I'm telling you. You'll meet him. No matter how far away we go, this island always draws us back home. 
Despite the accusations against him, Chin is an honest cop through and through although Chin has expressed some hurt at the fact that many of his former HPD colleagues and family (excluding Kono) don't trust him at times.
Chin is also extremely loyal towards his family, having unknowingly sacrificed his own career for the sake of protecting his uncle from the fallout.
Chin is very protective of his cousin, Kono.
Like the respect of his H50 colleagues, Chin has a strong loyalty towards Steve with Chin stating that he has found a home with H50, suggesting he is happy with his job as a H50 member and that he does not wish to return to the HPD.
Chin is a slim man of Asian decent with wavy/curly brown hair and brown eyes. The length of his hair changes from "long" to short as the series progresses.
When relaxing at the beach with friends or family, he is often seen wearing shorts, a loose t-shirt, and sandals. When working he has no distinct style. Unlike the HPD officers, H50 does not have an official uniform. His daily outfits will vary from tight fitting shirts with jeans to traditional Hawaiian floral t-shirts. On his waist, to the right side, he has his gun and badge, which is shown prominently.
When knowingly going into the line of fire or investigating a scenario that may present danger, he will wear a shirt that is neutral colored with a black bullet proof vest that has a small patch on the chest which displays their name and the department. On the front of his ves,t he has a row of extra shells for his shotgun, holsters for what appears to be items the size of pocket knives, gloves. On the bac,k there is a small pack. Unlike when in regular attire, his gun and holster is located on his right thigh.
In both regular attire and active duty attire, there is always a silver watch present on his left wrist.
The third-in-command of the H50 Task Force second to Steve and Danny, Chin is exceptionally skilled in weaponry and technology, his skills a close second to Steve's.
- Hand to Hand Combat - Chin is skilled in hand-to-hand combat and can easily hold his own.
- Technology - Chin is skilled at using the technology that the Five-0 team has at their disposal. Chin is always seen with a piece of technology on him and is even capable of retrieving off a damaged phone or an SD card.
- Profiling - Given his experience as a cop, Chin can get into the criminal's mind and even accurately predict their next move.
- Interrogation - Chin is skilled at interrogating.
- Firearms - Like the members of H50, Chin is an expert in weaponry and is seen usually wielding a SIG-Sauer P229R although he has been seen wielding a Benelli M1 Super 90 (Short Barrel)
- Chin Ho Kelly is the only character to appear in every episode until season 8.
- Kono Kalakaua is the only original cast member not to spend time in jail. Steve McGarrett spent just over a week in Halawa Correctional Facility.  Chin spent 8 hours in Halawa Correctional Facility,  and was arrested 2 years later. . And Danny Williams spent a few days in a Colombian prison. 
- Chin speaks English, and a little Korean, and Spanish. 
- Was offered a position to start his own Task Force in San Diego with Abby Dunn. 
|Ha'i'ole||Ua Lawe Wale||Kame'e||Mea Makamae||Ma'eme'e||Ka Hakaka Maika'i||Ka Iwi Kapu||Lapa'au||Ike Maka||Kil'ilua||Pahele||Alaheo Pau'ole|
|Ka Ho' Oponopono||Pu'olo||Mai Ka Wa Kahiko||I Helu Pu||Kupale||Lekio||Kalele||Ha'alele||Pa Make Loa||Ua Hopu||Ua Hala|
|Hawaii Five-0 Characters|
|Final|| Steve McGarrett • Danny Williams • Adam Noshimuri • Tani Rey • Junior Reigns • Lou Grover • Kamekona Tupuola • Duke Lukela • Noelani Cunha • Quinn Liu|
|Former|| Chin Ho Kelly • Kono Kalakaua • Max Bergman • Catherine Rollins • Jerry Ortega|
|Other||Lori Weston • Mary McGarrett • Grace Williams • Charles Williams • Jenna Kaye • Dr. Malia Waincroft|